Casts are widely used in the medical field to immobilize or restrain body parts which have suffered injury or are otherwise in need of immobilization or restraint. Casts were traditionally constructed of medical gauze and a plaster of paris compound. A significant disadvantage of plaster of paris casts was their inability to maintain structural integrity upon prolonged exposure to or immersion in water or other liquids. This inability prevented persons in casts from engaging in daily activities such as showering or bathing. The inability to withstand exposure to liquids caused special hardship to active people, especially young adults and children because it prevented them from participating in water activities such as swimming, boating, or water-skiing. Furthermore, even when not exposed to external sources of water or moisture, active individuals wearing casts often perspire under the cast, creating a source of moisture on the surface of the skin inside the cast. This moisture generally includes salts and other biological chemicals which can build up on the skin and cause an irritation such as "itching" which can be bothersome to the individual.
More recent cast construction techniques employ a three-part cast typically comprising: (a) a non-rigid sleeve consisting of a cloth padding as an underlayer dressing material placed onto the body surface; (b) a layer of resilient padding positioned around this underlayer; and (c) a rigid outer immobilizing layer typically consisting of a cured fiberglass webbing material.
Although fiberglass casts generally maintain their structural integrity when exposed to or immersed in water or other liquids, physicians and other medical practitioners continue to advise patients to avoid significant contact with water or other liquids. Reasons for avoiding prolonged contact with water can include the following: (a) when wet, the inner cloth sleeve and layer of resilient padding may act as a host for bacteria, thereby serving as a source of infection; (b) when wet, the inner sleeve and layer of resilient padding may prevent adequate air flow to the skin of the surrounded body member, thereby damaging the general health of the skin.
Thus, although improved cast construction techniques have minimized the risk of damage to the cast resulting from exposure to or immersion in liquids, practitioners mindful of the risk set forth above, and perhaps conditioned to provide advice which was very important in the past when casts were commonly made of plaster of paris continue to advise people wearing casts to avoid exposing the cast to water when showering, swimming, or boating. Therefore, in spite of the changes in cast construction, this problem continues to impose serious hardship on persons required to wear casts to immobilize injured limbs who enjoy aquatic sports such as swimming, water skiing, or boating. The present invention provides solutions to these and other problems.